Problem: Christopher starts counting at 48, and he counts by fives. If 48 is the 1st number that Christopher counts. what is the 8th number that he counts?
Solution: What is the first number that he counts? $48$ What is the second number that he counts? $\begin{align*}&48 + 5 \\ &= 53\end{align*}$ What is the third number that he counts? $\begin{align*}&48 + 5 + 5 \\ &= 48 + (2 \times 5) \\ &= 58\end{align*}$ What is the 8th number that he counts? $\begin{align*}&48 + (7\times5) \\ &= 48 + 35 \\ &= 83\end{align*}$